main.tf

resource "aws_security_group" "alb-sg" {
  name   = "ALBSecurityGroup"
  vpc_id = var.vpc_id
  tags = {
    Name = "TF_ALBSecurityGroup"
  }

  ingress {
    from_port   = 80
    protocol    = "tcp"
    to_port     = 80
    cidr_blocks = ["0.0.0.0/0"]
  }

  egress {
    from_port   = 0
    protocol    = "-1"
    to_port     = 0
    cidr_blocks = ["0.0.0.0/0"]
  }
}

resource "aws_alb" "app-lb" {
  name               = "phonebook-lb-tf"
  ip_address_type    = "ipv4"
  internal           = false
  load_balancer_type = "application"
  security_groups    = [aws_security_group.alb-sg.id]
  subnets            = var.subnets 
}

resource "aws_alb_listener" "app-listener" {
  load_balancer_arn = aws_alb.app-lb.arn
  port              = 80
  protocol          = "HTTP"
  default_action {
    type             = "forward"
    target_group_arn = aws_alb_target_group.app-lb-tg.arn
  }
}

resource "aws_alb_target_group" "app-lb-tg" {
  name        = "phonebook-lb-tg"
  port        = 80
  protocol    = "HTTP"
  vpc_id      = var.vpc_id
  target_type = "instance"

  health_check {
    healthy_threshold   = 2
    unhealthy_threshold = 3
  }
}